Hey guys so a few months ago I went SC and bought a used Novi 1000 kit. Since then I have upgraded to ID1000 injectors and gone AEM EMS v2 and tuned at Ballade Sports here in SoCal. I'm running the standard Comptech belt and aftercooler. I have run into an issue and I thought that you guys with more experience could help me out.

VTEC was a lowered to 4800. Once in VTEC my wideband shows in the lower 10s AFR. Often it shows just 10.00 from VTEC till redline. Sometimes around 6-7k RPMS by car will sputter and back fire. It probably does it half the time. I contacted Alex at Ballade and he seems to think that the belt could possibly be slipping causing too much fuel to enter the motor with no air from the SC. This will cause the car to back fire. I don't hear the belt slip at all but my Greddy TIC is really loud so it could be drowning out the sound.

My concern is that I'm pretty sure the AEM UEGOs lowest reading is 10.00. Could this possibly mean my car is running ever more rich but my wideband can't show it? At first I thought he gave me a very conservative tune since I wasn't going after any large numbers but now I'm kind of worried. Does any have any other suggestions as to why the car back fires?

I really hope this isn't all caused by a crappy tune but I guess anything is possible at this point. Any help would be great.

Thanks

 

Belt slip is common after the initial install before it breaks in, and it always requires a re adjust after a wile. Your boost gauge should be showing this slippage though if your no longer reaching your target afr at redline, that is one way to verify. But it sounds like your getting rich running symptoms, which are also associated with belt slip as mentioned. Your backfiring is very likely the result of too much fuel. 10 afr is as low as it reads, so if at any time it is pinned there, it is likely going richer which is flooding the motor. Check and re tighten your belt if needed. You should not be able to twist the belt more then about 90 degrees with your thumb and first finger. Stick your hand between the blower and after cooler to feel the belt tension, make sure the car is cold or you will be a burn victim.

 

Thanks Junky, you've been a big help answering my other questions as well. I really don't think the belt is slipping. I truly believe the car is running to rich and is getting flooded. Should I be concerned about the health of my motor or will leaning the car out be all I need?

 

+1
That is way too rich...bet you look like you are crop dusting too?

 

So has your AFR been showing that low post-VTEC ever since you got the tune? If so, then it just sounds like the tune has you running too rich.

 

I haven't noticed but I bet it looks like I'm blanketing an area with smog

Yes. I noticed it immediately, I thought it was because he gave me a safe tune but I'm starting to think the tune is running me very rich

 

Is it sputtering, bucking, loosing power or just backfiring?

I have a similar setup - Comptech Novi 1000, aftercooler, DW1000 injectors, AEM v2, AEM wideband, stock map but I'm running a 3.6" pulley with just under 10lbs of boost. I am still a rookie at all of this, but I've learned a lot quickly. I doubt it's just a loose belt unless it's super droopy. Very likely tuning issues though. ID1000's are big injectors for a base kit. I am still running a bit rich and believe the big injectors are at least a small part of my problem. My fuel numbers are really low compared to other cals I've seen with smaller injectors.

After the upgrades from the based kit I had an awful tune that pulled a solid 345 on the dyno. On the street it was a different story. It would pull hard to redline but buck like crazy going to 2nd. Steady speed bucking... Really not drivable.

You couldn't use it, but I can send you my cal file for some comparisons. I'm still a bit rich and dyno'ed low 340's with the current tune.

 

Sputtering, losing power, and backfiring. It's all happening at high RPMs though 6.5k RPMS or higher. It never happens below these RPMS
I addressed the injectors with my tuner but he said might as well get 1000s in case you increase boost in the future. I good tune should prevent my car from running this rich regardless of injectors I would think

 

It sounds like the tune to me man. has your tuner tuned other s2k's in the past? If not I would go somewhere else.

 

It sounds like the tune...I got one on my nv1000 that was "safe" and it showed 10's in boost. I went to change the oil and could smell gas in the oil...even off the dipstick. I would certainly raise these questions with the tuner...I would think a bit above 12 in boost would be "safe".